1. Field of the Invention
The present invention relates to a rotating electric machine including a rotor in which permanent magnets are arranged.
2. Description of the Related Art
The following AC generator for a vehicle is conventionally known as a magnet-type rotating electric machine. Specifically, permanent magnets are arranged on an inner wall surface of a bowl-like shaped flywheel so that the adjacent permanent magnets are magnetized to have opposite polarity patterns (for example, see Japanese Patent Application Laid-open No. 2008-193785; FIGS. 1 and 2).
In the above-mentioned AC generator for a vehicle, the flywheel rotates interlockingly with a rotary shaft which is rotationally driven by an internal combustion engine. By alternating magnetic fields generated by the permanent magnets, power is generated from magneto coils provided inside of the flywheel.
In the above-mentioned kind of magnet-type rotating electric machine, an output can be increased by increasing the amount of used permanent magnets or by using magnets excellent in magnetic characteristics. In such a case, however, there is a problem in that the magnet-type rotating electric machine is disadvantageously increased in size as well as in cost.